Low-water alarm for steam-boilers.



' No. 811,214. PATENTED JAN. 30, 1906.

G. G. GILDARD. LOW WATER ALARM FOR STEAM BOILERS.

APPLIGATION FILED JAN. 12. 1905.

2 SHEETSfiSHEB T 1.

@U; masses,

PATENTED JAN. 30, 1906.

0. G. GILDARD. LOW WATERALARM FOR STEAM BOILERS.

' APPLICATION FILED JAN.12. 1905.

ZSHBETS-SHEET 2.

M w 7 W 1% al liuawmg STATES T @TQE.

LOW-WATER FOR STEAM-BOILERS.

Specification of Letters Patent.

Patented Jan. 30, 1906.

Original application filed November 10, 1904, Serial No. $2,164. Divided and this application filed January 12, 1905. Serial To (1 107mm at may concern:

Be it known that I, CHRISTOPHER G. GIL- DARD, a citizen of. the United States, residing at Swansea, in the county of Bristol and- State of Massachusetts, have invented a Low- Water Alarm for Steam-Boilers, of which the following is a specification.

My invention relates to improvements in low-water alarms for steam-boilers.

' The invention has particular reference to an attachment to that class of boilers and their auxiliaries as employed in steam-automobiles, wherein is used a fusible-plug attachment and in which when the water reaches a certain point the fusible plug being exposed to the heat of the burner and no longer surrounded by water quickly melts and is blown out by the pressure of steam contained in the boiler. One of the disadvantages of this class of automobiles results from the fact that when the water becomes low and the plug is melted and discharged the steam escapes and it becomes necessary before proceeding for the operator to pump up to the proper level the water in the boiler by means of an auxiliary hand-pump and raise the steam to its normal pressure or thereabout. Such operation is preceded, of course, by the removal of the tube or pipe employedto carry the plug and the renewal of the plug in saidtube and the insertion of the latter in position or else the insertion of a substitute tube or pipe already plugged for-the occasion.

The objects of my invention are, first, to save the steam-pressure, or, in other words, to prevent the same from being reduced or lowered by reason of the blowing out of the plug; second, to sound an audible alarm as a warning to the operator that the plug has been blown and that the water is therefore dangerouslylow, and, third, to provide for an immediate and automatic cutting off of the 'gasolene supply, whereby even though the operator failed to note the alarm, yet the boiler cannot be burned or scorched.

Other obj sets and advantages of the invention will hereinafter appear, and the novel features thereof will be particularly pointed out in the appended claims.

lteferringto the drawings, Figure 1 is a view showing my improved system, the fusi ble plug being in position. Fig. 2 is a similar view showing the same parts as they will appear after the fusible plug has been melted and blown out, and therefore the water below the normal water-line. Fig. 3 is a vertical longitudinal sectional view through the fusible-plug attachment hereinafter referred to. Fig. 4 is a transverse sectional view taken on the line4 4 of Fig. 3. Fig. 5is a detail perspective view of a removable threaded plug for closing the lower end of the sliding sleeve.

Like numerals of reference indicate like parts throughout the drawings.

1 designates the main vaporizer, at the outer end of which is located the vaporizingnozzle 2 for injecting the gasolenc-vaporinto the mixing-chamber of the burner. (Not shown.)

3 designates the main gasolene-supply, which is coupled, as at 4, to that end of the vaporizer 1 opposite the vaporizing-nozzle 2 and has located at some point most convenient a cut-off 5, which is normally open.

6 designates the tube or pipe which leads from an opening in the under side of the usual fire-tube boiler and projects to a point near an opening in the boiler-casing. Threaded removably within the outer end of the tube 6 is the fusible-plug tube or pipe 7, the fusible plug being indicated, as at 8, by dotted lines.

The tube 7 has heretofore been left, as above the purpose of unscrewing when the fusible plug shall have been blown out. In the present instance, however, 1 thread upon the outer end of the tube 8 an elbow 9, connecting it to a tube 10, which may have located therein a cutoff or valve 11, provided at its outer end with an angular stud or stem 12. Upon this stud or stem 12 I may removably mount a bell-crank 13, usin a cotter-pin 14 or other fastening device for temporarily securing said bell-crank in position. The lower end of the tube or pipe 10 may be formed with a disk-like head 15, (see Fig. 3,) and mounted on said tube or pipe so as to slide is a cylindrical sleeve 16, the upper end of which fits closely about the tube orpipe 10 and the lower end of which is open and internally threaded.

The internal diameter of the sleeve 16 substantially agrees with the diameter of the disk-like head 15, and between the latter and the upper end of the sleeve a coiled spring 17 of the compression type is located, the tendency of which spring is to normally elesaid head and the wall of the sleeve 16.

vate the sleeve against a washer 18, likewise mounted on the tube or pipe 10.

Threaded removably in the lower end of the sleeve 16 is a cap or plug 19, (see Figs. 3 an 5,) the same being externall threaded, as shown, to fit the lower end 0 the sleeve and provided on its under side with a squared boss 20 to receive a'wrench and by means of which it may be removed or set in position. This cap is further formed with a central perforation 21, and mounted for reception there on is a stem 22, which extends above and below the cap. At its upper end the stem carries a head 23, preferably of angular shape, so

as to leave a clearance between the sides (I): coiled compression-spring 24 is interposed between this head and the upper side of the cap 19 and serves to normally elevate the head 23. The latter has located upon its upper side a stud 25, which coming against the under side of the disk-like head 15 spaces the two heads apart and prevents close contact. The

stem 22 has located in its lower end an ordinary cotter-pin 26 to maintain it in position.

From the lower end of the sleeve 16 there may exend a pair of horizontal ears 27 ,and the twomay be connected to the upper end of the bell-crank lever 13 b a link 28.

A rock-shaft 29 is locate in suitable transversely opposite bearings 30, secured to the under side of the burner or framework of the automobile, and depending from the rockshaft and moving therewith are rock-arms 31 and 32. A' connecting-rod 33 connects the lower end of the rock-arm 32 with the corresponding end of the bell-crank 13, anda similar rod 34 connects the lower end of the rockarm 31 with the corresponding rock-arm 35, removably mounted upon the angular stem 36 of the cut-off or valve 5 in the main gasolene-pipe 3.

' There maybe located in the path of the rock-arm 31 or of any one of the before mentioned rock-arms a spring-latch 37, the shouldered head 37 X of which 1s designed to engage with the aforesaid rock-arm when the latter moves forward, as shown in Fig. 2., and hence the valve 5 in the main gasolene-supply closed. This latch of course is capable of belng sprung to one side by hand, so as to release the engaged rock-arm when desired.

38 designates a contact-arm, the same being secured by a screw 39 to a convenient portion of the framework and insulated thererom, as at 40. The lower end of this arm is outwardly bent, as at 41, to lieimmediately under the lower end of the movable portion carried by the pipe or tube 10, which would be the stem 22, whereby when the sleeve 16 is lowered on the pipe a contact with the arm 28 is made. I 1

42 designates in this instance a buzzer, or it may be any form of, audible alarm, and from the samethere leads a connecting-wire or electrical conductor 43, the opposite end of the conductor being connected by the screw 39 with the aforesaid contact-arm 38. An electrical connection 44 serves to connect an opposite wire 45 with the main vaporingtube '1 and the buzzer oriother alarm 42, one or" more batteries 46 being located in said circuit. It will be obvious that when the sleeve is lowered so as to complete a contact with the arm 38 the circuit will then be complete, in that. the same will pass from one pole of the battery, throu h the wire conductor 45, to the main gaso ene-pipe 3, to the rock-arm 35, through the rod 34 and the rock-arm 31 ,from the latter to the rock-shaft 29 to the rock-arm 32, from thence through the connecting-rod 33 to the' bell-crank, and through the pipe 10 to the sleeve 16, the plug or cap 19 and to the stem 22, from thence to the contact-arm 38, and from the latter to the conductor 43 and back to the battery through the alarm, which .will be sounded, and thus warn the operator of the condition of the boiler.

Taking the parts in the position shown in Fig. 1, we will suppose that the water in the boiler has reached a point below the fusibleplug tube and that the plu being ex osed to the heat of the burner as melte and blown out by the pressure of steam. The steam will be conducted immediately through the elbow 9 and pipe 10, where it will contact with the head 23, causing the latter, with the stem 22 thereof, to be forced downward, carrying with it the sleeve 16, against the ten-- IOO sion of the spring 17. This will cause the stem 22 to contact with the contact-arm 38] I event the automobile is left standing unattended and the fusible plug should blow out the main fire will be cut off automatically and the operator upon returning to the vehicle will be unable to turn on the main fire and will necessarily be obliged to disconnect the latch 37 from the rock-arm 31, in which event he will be ap rised of the fact that he has blown out the p ug and should not relight his fire until he has replenished the water in the boiler by means of the auxiliary handpump provided for that purpose. It will be obvious, furthermore, that when the head 23 is forced downward the valveface 47, formed on the under side of the head, will abut against the upper side of the cap or 'plug 19, thus preventing the escape of steam through the opening 21 in said plug or cap, so that the pressure of steam is maintained. This will enable the operator to proceed on his j our- ,ney without the necessity of removing the steam to the sleeve 16, thus allowing the sleeve to retract and the alarm cease. If

preferred, I may omit this valve and simply mount the bell-crank lever 13-upon a stud and permit the steam to escape into the sleeve 16, thus keeping up a continuous alarm. It will be obvious that when the bellcrank lever is operated as described it will, through the-medium of the connecting-rod 33, swing the rock-arms 31, 32, and 35 forward, thus cutting off the gasolene-supply at the valve 5 and locking the rock-arm 31, so that the main burner cannot be again turned on until the latch 37 is disconnected from the rock-arm 31.

It will be obvious that by removing the bell-crank lever 13 from the stud 12 the sleeve and tube or pipe 10, carrying the same, may be removedwith its elbow from the fusibleplug-carrying tube or sleeve 7 and either the plug renewed and the parts replaced or a new plug-carrying pipe or tube inserted in its place and the sliding sleeve,'togetherwith the parts carried thereby, replaced and the bellcrank lever again mounted on the stud 12.

As is well known, the fusible plug seldom for any length of time completely closes the fusible-plug tube or pipe 7, and the result is that there is alwa s more or less dripping from the pipe or tube. This dripping is provided for by reason of the angular-headed valve 23, which by reasonof its shape produces at its four sides clearance-openings, as shown in Fig. 4, so that the drip may pass out through the hole 21 in the bottom cap or plug 19.

Certain novel features of construction herein illustrated and described, but not claimed, form the subject-matter of a companion pending ap licationnamely, Serial No. 232,164, filed ovember 10, 1904, and of which this application is a division.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-- 1. The combination with the fusible-plug pi e of a steam-boiler, of an electrical contact a apted to be actuated by the pressure of steam escaping from said fusible-plug pipe, a second contact arranged in the path of the first, a source of electrical energy, conductors leading to such contact, and an alarm located in the electrical circuit.

2. The combination with the fusible-plug pipe of a steam-boiler, of an electric contact adapted to be actuated by the pressure of steam escaping from said pipe, a second contact arranged in the path of the first, a source of electric energy, conductors leading to each contact, and an alarm located in the electric circuit, a cut-oil arranged in the path of and connected to the fusible-plug pipe, and means actuated by the movable contact for operating said cut-off.

3. The combination with the fusible-plug pipeof a steam-boiler, of a pipe connected to the outer end thereof, a sliding sleeve mounted on said extension, a contact arranged in the path of the sleeve, conductors connected with said. contact and with said sleeve, a source of electric energy, and an alarm arranged in the circuit.

4. The combination with the fusible-plug pipe of a steam-boiler, of an extension coupled thereto, a valve located in the extension, a sleeve mounted on the extension beyond the valve, a contact arranged in the path of the sleeve, electric conductors'leadin to the contact and to the sleeve, a spring or normally supporting the sleeve, means connected with the sleeve and with the valve whereby the latter is operated by the movement of the sleeve against the tension of the s ring, a

source of electric energy, and an a arm arranged in the circuit. 5. The combination with the fusible-plug pipe of a steam-boiler, of an alarm adapted to e actuated by the escape of steam therefrom, and a valve adapted to be actuated,

, cuit.

7. The combination with the fusible-plug pipe of a steam-boiler, of an'extension cou pled to the same and terminating at itslower end in a head, a sleeve mounted to reciprocate on the extension and depending below the head, a coiled spring interposed between I the end ofthe sleeve and the head, a plug or cap in the lower end of the sleeve and provided with an opening, a valve-stem arranged in the opening and adapted to close the same a spring for normally, elevating the valvestem a contact arranged in the path of the valve stem, a source of electric supply, an alarm, and conductors leading from the electric supply and alarm to the contact and to the sleeve.

8. The combination with the fusible-plug pipe of a steam-boiler, of an alarm, an electrical circuit, and means actuated by the escape of steam from the fusible-plug pipe for closing the electrical circuit and sounding an a arm;

IIO

9. The combination with the fusible-plug pipe of a steam-boiler, of an extension thereof, a valve locatedin the extension and adapted to be closed by the escape of steam from the fusible-plug pipe, an electric contact carried by the extension and adapted to be actuated by the escape of steam from the fusibleplug p1' e, a contact-arm, an electric circuit to the atter, and an alarm arranged in the circuit.

10. The combination with the fusible-plug pipe of a steam-boiler, of an extension-pipe coupled thereto and terminating at its lower end in a head and provided above the same With a valve having a stem extending outward therefrom, a slidin sleeve mounted onthe extension above the head, a coiled spring inserted between the sleeve and the head, a bored cap in the lower end of the sleeve, a stem 22 mounted in the bore and having at its upper end an angular head 23 and below the same a valve 47 for closing the bore, a spring for normally elevating the head 23, a contact-arm arranged in the path of the stem 22, an electric circuit connected to said contact-arm and the sleeve, an alarm arranged in the circuit.

In testimony whereof I have signed my 'name to this specification in the presence of two subscribing Witnesses.

CHRISTOPHER G; GILDARD. Witnesses:

AnoLPHUs T. CASTELLANA, NICHOLAS HATHEWAY, Jr. 

